Presettable polarizing key for electrical connectors

ABSTRACT

A polarizing or keying system wherein the keyed elements in a mating pair of connectors can be selectively preset in any of a number of positions. The keyed element in one connector is polygonal in external cross-section, so that it can be selectively inserted with its keyway in various rotational positions in a correspondingly shaped polygonal opening in the dielectric body of the connector. The connector can then be mated only with a unit in which the coacting key is correspondingly oriented. The keyed element has a shoulder engaging the dielectric body; when the keyed element is retained by fastening means engaging an outer shell, the dielectric body is in turn retained in the shell by the keyed element.

United States Patent 1 1' Haffner et al.

1 1 PRESETTABLEPOLARIZING KEY FOR ELECTRICAL CONNECTORS [75] Inventors:Helmut Hubert Haffner, l-leilbronn;

Lothar Karl Kannheiser, Neckarsulm; Kuno Wilhelm Schmied, Eschenau, allof Germany [73] Assignee: Bunker Ramo Corporation, Oak

Brook, 111.

[22] Filed: Mar. 27, 1972 [21] Appl. No.: 238,394

[30] Foreign Application Priority Data 18 l2 ll 31 I Nov. 6, 19733,023,394 2/1962 l-lubbell 339/186 M FOREIGN PATENTS OR APPLICATIONS730,731 12/1942 Germany 339/186 R 961,714 6/1964 Great Britain 339/184 M1,474,721 2/1967 France 339/184 M 767,844 2/1957 Great Britain 339/186 MPrimary Examiner-Ernest R. Purser Assistant ExaminerLawrence J. StaabAttorney-Frederick M. Arbuckle [57] I ABSTRACT A polarizing or keyingsystem wherein the keyed elements in a mating pair of connectors can beselectively preset in any of a number of positions. The keyed element inone connector is polygonal in external crosssection, so that it can beselectively inserted with its keyway in various rotational positions ina correspondingly shaped polygonal opening in the dielectric body of theconnector. The connector can then be mated only with a unit in which thecoacting key is corre- .spondingly oriented The keyed element has ashoulder engaging the dielectric body; when the keyed element isretained by fastening means engaging an outer shell,

the dielectric body is in turn retained in the shell by the keyedelement.

1 Claim, 3 Drawing Figures BACKGROUND OF THE INVENTION 1. Field of theInvention This invention relates to the field of electrical connectors,particularly connectors in which one part is keyed or polarized so thatit can only mate with a second part which is similarly polarized. Thepolarizing elements can be preset in any one of several predeterminedpositions.

2. Description of the Prior Art In a conventional connector of thistype, a housing is provided with an inwardly extending indexing pin atthe side opposite to an inserted contact set. A corresponding codingmember terminates in the form of an indexing sleeve, into which theindexing pin can be inserted. Both the indexing pin and the indexingsleeve are provided with interlocking indexing shoulders.

The contact set inserted into the housing is provided with an openingaligned with the indexing pin. A coding member is pushed into thisopening (after the contact set has been inserted), until the indexingpin snaps into the indexing sleeve. A shoulder provided at the codingmember supports the contact set in the housing. Both the indexing pinand the coding member are provided with a hole for accepting a screwwhich passes through the housing from the side opposite to the contactset and which joins the two connector parts after they have been pluggedtogether. The disadvantage of the connector of this type is that thecoding member, once it has been inserted, can be detached only by meansof a special tool which must be introduced from the side of the contactset. Thus, the coding can be modified only when such a special tool isavailable.

SUMMARY OF THE INVENTION It is an object of the invention to provide animproved keyed connector havirig a keying member which can be easilydetached from the connector without requiring special tools in order toset the connector in one of several predetermined keyed positions.

According to the invention, afrst connector part of the assembly has ahousing with a retaining sleeve extending through a wall in the housing.A first keying member is positioned within the first connector part inone of several predetermined positions. This first member has anindicating portion detachably engaged with the retaining sleeveaccessible through the sleeve for detachment therefrom.

A second connector part mates with the first connector part, and has asecond keying member positioned therein which is engageable with thefirst keying member when the two are in appropriately keyedrelationship, permitting the first connector part to be joined to thesecond connector part only when such appropriately keyed relationshipexists.

In a preferred embodiment, the first keying member is a pin which issplit by a transverse slot at one end to form resilient tongues, one ofwhich is provided with a latching shoulder by which the keying member isretained in the housing. The advantage of this configuration is that thekeying member can be easily detached by pressing an object such as ascrewdriver or other simple tool introduced into the sleeve from theoutside against the tongue provided with the latching shoulder,

to release the latching engagement so that the keying 7 member can bepushed out of the connector.

It is advantageous to provide the end of the keying member whichprotrudes from the indexing sleeve with a mark such as a grooveindicating the position of the keyway of the keying member in thehousing. Thus, the position of the keyway in the housing can be readfrom the outside without unmating the connectors.

Furthermore, it is advantageous to provide markings on the housingsurrounding the opening of the indexing sleeve to facilitate the readingof the position of the keying member in the housing.

BRIEF DESCRIPTION OF THE DRAWINGS Other features and advantages of thepresent invention are outlined in the following description of anembodiment to be taken in conjunction with the drawings. In thedrawings:

FIG. 1 is a top view of the cable accepting connector part;

FIG. 2 is a longitudinal section through a cable ac,- cepting connectormated to an instrument connector part; and

FIG. 3 is a bottom view of the cable accepting connector part.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 2, theconnector comprises a connector part 1 for accepting the cable and aconnector part 2 for joining to the side of an instrument. Connectorpart 2 is provided with contact blades 3 which end in cable-connectingterminals 4 at the side of the instrument. A dielectric body 6 carryingcontact jacks 5 is inserted in housing 16 of the connector partaccepting the cable. Contact jacks 5 carry cable-clamping terminals 7 atthe side at which the cable is introduced. In addition, connector part 1is provided with a packing 40. gland 8 into which a cable'(not shown) isclamped.

Each connector part 1, 2 is provided with a keying member 9, 10,respectively, so that connector part can be joined only when theirassociated keying members are appropriately oriented. Keying member 9 inthe connector part accepting the cable has the form of a sleeve, one endof which, at 13, has an outer surface which is octagonal incross-section, and has an internal keyway 15. At theopposite end, themember 9 has a reduced diameter portion 11 formed with a transverse slot28 to provide a pair of radially resilient tongues 30, 31. The tongueshave conical surfaces at their ends, to facilitate entry into aninternally directed boss 17 in housing 16, and tongue 31 has a latchingshoulder 12 which engages with an oppositely facing internal shoulder 18in the boss 17. This engagement provides snaplock retention of member 9in housing 16.

Member 9 has a shoulder 19, separating its portion 13 from the reduceddiameter portion 11, which engages a corresponding shoulder indielectric body 6,

. and thereby retains the latter in housing 16 when the keying member 9is in its position.

Connector part 2 has a dielectric body 21 which carries a keying member10 having an upstanding pin 22 which has an axially extending key 23along one side. The pin is adapted to be received in the socket end 13of keying member 9, with the key 23 fitting in the keyway 15. The keyingmember 10 can be rotationally oriented in the body 21 in any of a numberof predetermined positions, and is retained in the selected position bya snap lock (not shown)..When the positions of the key 23 and the keyway15 correspond appropriately in orientation, connector parts 1 and 2 canbe fully joined, but not otherwise.

In addition, keying member is provided with a threaded insert 24 foraccepting a screw 25 which retains the two connector parts in theassembled position.

A groove 26 is provided across the end of tongue 31, in alignment withthe keyway 15. This makes it possible to read the position of the keywayin keying member 9 in connector part 1 from the outside, when screw 25has been removed. in order to facilitate the readings a scale 27consisting of eight letters is provided at the edge of the outer openingfrom boss 17 (FIG. 1); one letter corresponds to each predeterminedposition.

In order to change the position in connector part 1 accepting the cable,screw 25 is loosened, and the two connector parts 1 and 2 are separated.By exerting a pressure upon the conical end of tongue 31 by means of ascrewdriver or a similar object, such as a ball-point pen, the snap-onlock of keying member 9 on housing 16 is opened; and the keying membercan be pushed out in the forward direction. After that, keying member 9is pushed into dielectric body 6 in a newpredetermined position, untiltongue 31 snaps into boss 17. After that, connector part 1 can be joinedwith a corresponding connector part which has been'appropriately coded.

From the foregoing, it can be readily realized that this invention canassume various embodiments. Thus, it is to be understood that theinvention is not limited to the specific embodiments described herein,but is to be limited only by the appended claims.

We claim:

1. Polarizing means for one of a pair of electrical connectors, whereinsaid one connector has a housing and a dielectric body therein carryingelectrical contacts, comprising, in combination,

a keying member,

said body having a recess adapted to receive said member, 1 therespective contours of said member and said recess being such as topermit reception of said member in said recess in any of a plurality ofdefinite pre-determined rotational positions,

a rotationally keyed structure on said member adapted to coact with areciprocally keyed structure on a mating connector, and

interengaging means on said body and said member,

whereby said member retains said body in said housing,

said keying member being a tubular element having axially extendingtongues, radially resilient at their extremities, one of said tongueshaving a latch engageable with a shoulder in said housing, whereby saidkeying member is retained within said housing,

said one of said tongues carrying a mark, from the position of which theorientation of said keying member can be ascertained without referenceto the face of said one connector which comes adjacent to the otherconnector of said pair when said connectors are joined.

, I l It l i

1. Polarizing means for one of a pair of electrical connectors, whereinsaid one connector has a housing and a dielectric body therein carryingelectrical contacts, comprising, in combination, a keying member, saidbody having a recess adapted to receive said member, the respectivecontours of said member and said recess being such as to permitreception of said member in said recess in any of a plurality ofdefinite pre-determined rotational positions, a rotationally keyedstructure on said member adapted to coact with a reciprocally keyedstructure on a mating connector, and interengaging means on said bodyand said member, whereby said member retains said body in said housing,said keying member being a tubular element having axially extendingtongues, radially resilient at their extremities, one of said tongueshaving a latch engageable with a shoulder in said housing, whereby saidkeying member is retained within said housing, said one of said tonguescarrying a mark, from the position of which the orientation of saidkeying member can be ascertained without reference to the face of saidone connector which comes adjacent to the other connector of said pairwhen said connectors are joined.